Question

To which group and period does the element with electronic configuration 2,8,4 belong in the modern periodic table?

[1 mark]

• A. $1^{st}period,1^{st}group$
• B. $3^{rd}period,{14}^{th}group$
• C. $3^{rd}period,3^{rd}group$
• D. $2^{nd}period,{15}^{th}group$

Answer 1

The correct option is B $3^{rd}period,{14}^{th}group$

The number of shells of an element determines the period number and the number of valence electrons determines the group number (except for group $3^{rd}to{12}^{th}$). The electronic configuration for the given element is 2,8,4.
There are 3 shells and 4 valence electrons. Hence, the element belongs to the $3{}^{rd}periodand{14}^{th}group$ in the modern periodic table.